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jidctred-sse2.asm (23213B)


      1 ;
      2 ; jidctred.asm - reduced-size IDCT (SSE2)
      3 ;
      4 ; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
      5 ; Copyright (C) 2016, 2024, D. R. Commander.
      6 ;
      7 ; Based on the x86 SIMD extension for IJG JPEG library
      8 ; Copyright (C) 1999-2006, MIYASAKA Masaru.
      9 ; For conditions of distribution and use, see copyright notice in jsimdext.inc
     10 ;
     11 ; This file should be assembled with NASM (Netwide Assembler) or Yasm.
     12 ;
     13 ; This file contains inverse-DCT routines that produce reduced-size
     14 ; output: either 4x4 or 2x2 pixels from an 8x8 DCT block.
     15 ; The following code is based directly on the IJG's original jidctred.c;
     16 ; see the jidctred.c for more details.
     17 
     18 %include "jsimdext.inc"
     19 %include "jdct.inc"
     20 
     21 ; --------------------------------------------------------------------------
     22 
     23 %define CONST_BITS    13
     24 %define PASS1_BITS    2
     25 
     26 %define DESCALE_P1_4  (CONST_BITS - PASS1_BITS + 1)
     27 %define DESCALE_P2_4  (CONST_BITS + PASS1_BITS + 3 + 1)
     28 %define DESCALE_P1_2  (CONST_BITS - PASS1_BITS + 2)
     29 %define DESCALE_P2_2  (CONST_BITS + PASS1_BITS + 3 + 2)
     30 
     31 %if CONST_BITS == 13
     32 F_0_211 equ  1730  ; FIX(0.211164243)
     33 F_0_509 equ  4176  ; FIX(0.509795579)
     34 F_0_601 equ  4926  ; FIX(0.601344887)
     35 F_0_720 equ  5906  ; FIX(0.720959822)
     36 F_0_765 equ  6270  ; FIX(0.765366865)
     37 F_0_850 equ  6967  ; FIX(0.850430095)
     38 F_0_899 equ  7373  ; FIX(0.899976223)
     39 F_1_061 equ  8697  ; FIX(1.061594337)
     40 F_1_272 equ 10426  ; FIX(1.272758580)
     41 F_1_451 equ 11893  ; FIX(1.451774981)
     42 F_1_847 equ 15137  ; FIX(1.847759065)
     43 F_2_172 equ 17799  ; FIX(2.172734803)
     44 F_2_562 equ 20995  ; FIX(2.562915447)
     45 F_3_624 equ 29692  ; FIX(3.624509785)
     46 %else
     47 ; NASM cannot do compile-time arithmetic on floating-point constants.
     48 %define DESCALE(x, n)  (((x) + (1 << ((n) - 1))) >> (n))
     49 F_0_211 equ DESCALE( 226735879, 30 - CONST_BITS)  ; FIX(0.211164243)
     50 F_0_509 equ DESCALE( 547388834, 30 - CONST_BITS)  ; FIX(0.509795579)
     51 F_0_601 equ DESCALE( 645689155, 30 - CONST_BITS)  ; FIX(0.601344887)
     52 F_0_720 equ DESCALE( 774124714, 30 - CONST_BITS)  ; FIX(0.720959822)
     53 F_0_765 equ DESCALE( 821806413, 30 - CONST_BITS)  ; FIX(0.765366865)
     54 F_0_850 equ DESCALE( 913142361, 30 - CONST_BITS)  ; FIX(0.850430095)
     55 F_0_899 equ DESCALE( 966342111, 30 - CONST_BITS)  ; FIX(0.899976223)
     56 F_1_061 equ DESCALE(1139878239, 30 - CONST_BITS)  ; FIX(1.061594337)
     57 F_1_272 equ DESCALE(1366614119, 30 - CONST_BITS)  ; FIX(1.272758580)
     58 F_1_451 equ DESCALE(1558831516, 30 - CONST_BITS)  ; FIX(1.451774981)
     59 F_1_847 equ DESCALE(1984016188, 30 - CONST_BITS)  ; FIX(1.847759065)
     60 F_2_172 equ DESCALE(2332956230, 30 - CONST_BITS)  ; FIX(2.172734803)
     61 F_2_562 equ DESCALE(2751909506, 30 - CONST_BITS)  ; FIX(2.562915447)
     62 F_3_624 equ DESCALE(3891787747, 30 - CONST_BITS)  ; FIX(3.624509785)
     63 %endif
     64 
     65 ; --------------------------------------------------------------------------
     66    SECTION     SEG_CONST
     67 
     68    ALIGNZ      32
     69    GLOBAL_DATA(jconst_idct_red_sse2)
     70 
     71 EXTN(jconst_idct_red_sse2):
     72 
     73 PW_F184_MF076   times 4  dw  F_1_847, -F_0_765
     74 PW_F256_F089    times 4  dw  F_2_562,  F_0_899
     75 PW_F106_MF217   times 4  dw  F_1_061, -F_2_172
     76 PW_MF060_MF050  times 4  dw -F_0_601, -F_0_509
     77 PW_F145_MF021   times 4  dw  F_1_451, -F_0_211
     78 PW_F362_MF127   times 4  dw  F_3_624, -F_1_272
     79 PW_F085_MF072   times 4  dw  F_0_850, -F_0_720
     80 PD_DESCALE_P1_4 times 4  dd  1 << (DESCALE_P1_4 - 1)
     81 PD_DESCALE_P2_4 times 4  dd  1 << (DESCALE_P2_4 - 1)
     82 PD_DESCALE_P1_2 times 4  dd  1 << (DESCALE_P1_2 - 1)
     83 PD_DESCALE_P2_2 times 4  dd  1 << (DESCALE_P2_2 - 1)
     84 PB_CENTERJSAMP  times 16 db  CENTERJSAMPLE
     85 
     86    ALIGNZ      32
     87 
     88 ; --------------------------------------------------------------------------
     89    SECTION     SEG_TEXT
     90    BITS        32
     91 ;
     92 ; Perform dequantization and inverse DCT on one block of coefficients,
     93 ; producing a reduced-size 4x4 output block.
     94 ;
     95 ; GLOBAL(void)
     96 ; jsimd_idct_4x4_sse2(void *dct_table, JCOEFPTR coef_block,
     97 ;                     JSAMPARRAY output_buf, JDIMENSION output_col)
     98 ;
     99 
    100 %define dct_table(b)   (b) + 8          ; void *dct_table
    101 %define coef_block(b)  (b) + 12         ; JCOEFPTR coef_block
    102 %define output_buf(b)  (b) + 16         ; JSAMPARRAY output_buf
    103 %define output_col(b)  (b) + 20         ; JDIMENSION output_col
    104 
    105 %define original_ebp   ebp + 0
    106 %define wk(i)          ebp - (WK_NUM - (i)) * SIZEOF_XMMWORD
    107                                        ; xmmword wk[WK_NUM]
    108 %define WK_NUM         2
    109 
    110    align       32
    111    GLOBAL_FUNCTION(jsimd_idct_4x4_sse2)
    112 
    113 EXTN(jsimd_idct_4x4_sse2):
    114    push        ebp
    115    mov         eax, esp                     ; eax = original ebp
    116    sub         esp, byte 4
    117    and         esp, byte (-SIZEOF_XMMWORD)  ; align to 128 bits
    118    mov         [esp], eax
    119    mov         ebp, esp                     ; ebp = aligned ebp
    120    lea         esp, [wk(0)]
    121    PUSHPIC     ebx
    122 ;   push        ecx                     ; unused
    123 ;   push        edx                     ; need not be preserved
    124    push        esi
    125    push        edi
    126 
    127    GET_GOT     ebx                     ; get GOT address
    128 
    129    ; ---- Pass 1: process columns from input.
    130 
    131 ;   mov         eax, [original_ebp]
    132    mov         edx, POINTER [dct_table(eax)]    ; quantptr
    133    mov         esi, JCOEFPTR [coef_block(eax)]  ; inptr
    134 
    135 %ifndef NO_ZERO_COLUMN_TEST_4X4_SSE2
    136    mov         eax, dword [DWBLOCK(1,0,esi,SIZEOF_JCOEF)]
    137    or          eax, dword [DWBLOCK(2,0,esi,SIZEOF_JCOEF)]
    138    jnz         short .columnDCT
    139 
    140    movdqa      xmm0, XMMWORD [XMMBLOCK(1,0,esi,SIZEOF_JCOEF)]
    141    movdqa      xmm1, XMMWORD [XMMBLOCK(2,0,esi,SIZEOF_JCOEF)]
    142    por         xmm0, XMMWORD [XMMBLOCK(3,0,esi,SIZEOF_JCOEF)]
    143    por         xmm1, XMMWORD [XMMBLOCK(5,0,esi,SIZEOF_JCOEF)]
    144    por         xmm0, XMMWORD [XMMBLOCK(6,0,esi,SIZEOF_JCOEF)]
    145    por         xmm1, XMMWORD [XMMBLOCK(7,0,esi,SIZEOF_JCOEF)]
    146    por         xmm0, xmm1
    147    packsswb    xmm0, xmm0
    148    packsswb    xmm0, xmm0
    149    movd        eax, xmm0
    150    test        eax, eax
    151    jnz         short .columnDCT
    152 
    153    ; -- AC terms all zero
    154 
    155    movdqa      xmm0, XMMWORD [XMMBLOCK(0,0,esi,SIZEOF_JCOEF)]
    156    pmullw      xmm0, XMMWORD [XMMBLOCK(0,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    157 
    158    psllw       xmm0, PASS1_BITS
    159 
    160    movdqa      xmm3, xmm0        ; xmm0=in0=(00 01 02 03 04 05 06 07)
    161    punpcklwd   xmm0, xmm0        ; xmm0=(00 00 01 01 02 02 03 03)
    162    punpckhwd   xmm3, xmm3        ; xmm3=(04 04 05 05 06 06 07 07)
    163 
    164    pshufd      xmm1, xmm0, 0x50  ; xmm1=[col0 col1]=(00 00 00 00 01 01 01 01)
    165    pshufd      xmm0, xmm0, 0xFA  ; xmm0=[col2 col3]=(02 02 02 02 03 03 03 03)
    166    pshufd      xmm6, xmm3, 0x50  ; xmm6=[col4 col5]=(04 04 04 04 05 05 05 05)
    167    pshufd      xmm3, xmm3, 0xFA  ; xmm3=[col6 col7]=(06 06 06 06 07 07 07 07)
    168 
    169    jmp         near .column_end
    170    ALIGNX      16, 7
    171 %endif
    172 .columnDCT:
    173 
    174    ; -- Odd part
    175 
    176    movdqa      xmm0, XMMWORD [XMMBLOCK(1,0,esi,SIZEOF_JCOEF)]
    177    movdqa      xmm1, XMMWORD [XMMBLOCK(3,0,esi,SIZEOF_JCOEF)]
    178    pmullw      xmm0, XMMWORD [XMMBLOCK(1,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    179    pmullw      xmm1, XMMWORD [XMMBLOCK(3,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    180    movdqa      xmm2, XMMWORD [XMMBLOCK(5,0,esi,SIZEOF_JCOEF)]
    181    movdqa      xmm3, XMMWORD [XMMBLOCK(7,0,esi,SIZEOF_JCOEF)]
    182    pmullw      xmm2, XMMWORD [XMMBLOCK(5,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    183    pmullw      xmm3, XMMWORD [XMMBLOCK(7,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    184 
    185    movdqa      xmm4, xmm0
    186    movdqa      xmm5, xmm0
    187    punpcklwd   xmm4, xmm1
    188    punpckhwd   xmm5, xmm1
    189    movdqa      xmm0, xmm4
    190    movdqa      xmm1, xmm5
    191    pmaddwd     xmm4, [GOTOFF(ebx,PW_F256_F089)]   ; xmm4=(tmp2L)
    192    pmaddwd     xmm5, [GOTOFF(ebx,PW_F256_F089)]   ; xmm5=(tmp2H)
    193    pmaddwd     xmm0, [GOTOFF(ebx,PW_F106_MF217)]  ; xmm0=(tmp0L)
    194    pmaddwd     xmm1, [GOTOFF(ebx,PW_F106_MF217)]  ; xmm1=(tmp0H)
    195 
    196    movdqa      xmm6, xmm2
    197    movdqa      xmm7, xmm2
    198    punpcklwd   xmm6, xmm3
    199    punpckhwd   xmm7, xmm3
    200    movdqa      xmm2, xmm6
    201    movdqa      xmm3, xmm7
    202    pmaddwd     xmm6, [GOTOFF(ebx,PW_MF060_MF050)]  ; xmm6=(tmp2L)
    203    pmaddwd     xmm7, [GOTOFF(ebx,PW_MF060_MF050)]  ; xmm7=(tmp2H)
    204    pmaddwd     xmm2, [GOTOFF(ebx,PW_F145_MF021)]   ; xmm2=(tmp0L)
    205    pmaddwd     xmm3, [GOTOFF(ebx,PW_F145_MF021)]   ; xmm3=(tmp0H)
    206 
    207    paddd       xmm6, xmm4              ; xmm6=tmp2L
    208    paddd       xmm7, xmm5              ; xmm7=tmp2H
    209    paddd       xmm2, xmm0              ; xmm2=tmp0L
    210    paddd       xmm3, xmm1              ; xmm3=tmp0H
    211 
    212    movdqa      XMMWORD [wk(0)], xmm2   ; wk(0)=tmp0L
    213    movdqa      XMMWORD [wk(1)], xmm3   ; wk(1)=tmp0H
    214 
    215    ; -- Even part
    216 
    217    movdqa      xmm4, XMMWORD [XMMBLOCK(0,0,esi,SIZEOF_JCOEF)]
    218    movdqa      xmm5, XMMWORD [XMMBLOCK(2,0,esi,SIZEOF_JCOEF)]
    219    movdqa      xmm0, XMMWORD [XMMBLOCK(6,0,esi,SIZEOF_JCOEF)]
    220    pmullw      xmm4, XMMWORD [XMMBLOCK(0,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    221    pmullw      xmm5, XMMWORD [XMMBLOCK(2,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    222    pmullw      xmm0, XMMWORD [XMMBLOCK(6,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    223 
    224    pxor        xmm1, xmm1
    225    pxor        xmm2, xmm2
    226    punpcklwd   xmm1, xmm4               ; xmm1=tmp0L
    227    punpckhwd   xmm2, xmm4               ; xmm2=tmp0H
    228    psrad       xmm1, (16-CONST_BITS-1)  ; psrad xmm1,16 & pslld xmm1,CONST_BITS+1
    229    psrad       xmm2, (16-CONST_BITS-1)  ; psrad xmm2,16 & pslld xmm2,CONST_BITS+1
    230 
    231    movdqa      xmm3, xmm5              ; xmm5=in2=z2
    232    punpcklwd   xmm5, xmm0              ; xmm0=in6=z3
    233    punpckhwd   xmm3, xmm0
    234    pmaddwd     xmm5, [GOTOFF(ebx,PW_F184_MF076)]  ; xmm5=tmp2L
    235    pmaddwd     xmm3, [GOTOFF(ebx,PW_F184_MF076)]  ; xmm3=tmp2H
    236 
    237    movdqa      xmm4, xmm1
    238    movdqa      xmm0, xmm2
    239    paddd       xmm1, xmm5              ; xmm1=tmp10L
    240    paddd       xmm2, xmm3              ; xmm2=tmp10H
    241    psubd       xmm4, xmm5              ; xmm4=tmp12L
    242    psubd       xmm0, xmm3              ; xmm0=tmp12H
    243 
    244    ; -- Final output stage
    245 
    246    movdqa      xmm5, xmm1
    247    movdqa      xmm3, xmm2
    248    paddd       xmm1, xmm6              ; xmm1=data0L
    249    paddd       xmm2, xmm7              ; xmm2=data0H
    250    psubd       xmm5, xmm6              ; xmm5=data3L
    251    psubd       xmm3, xmm7              ; xmm3=data3H
    252 
    253    movdqa      xmm6, [GOTOFF(ebx,PD_DESCALE_P1_4)]  ; xmm6=[PD_DESCALE_P1_4]
    254 
    255    paddd       xmm1, xmm6
    256    paddd       xmm2, xmm6
    257    psrad       xmm1, DESCALE_P1_4
    258    psrad       xmm2, DESCALE_P1_4
    259    paddd       xmm5, xmm6
    260    paddd       xmm3, xmm6
    261    psrad       xmm5, DESCALE_P1_4
    262    psrad       xmm3, DESCALE_P1_4
    263 
    264    packssdw    xmm1, xmm2              ; xmm1=data0=(00 01 02 03 04 05 06 07)
    265    packssdw    xmm5, xmm3              ; xmm5=data3=(30 31 32 33 34 35 36 37)
    266 
    267    movdqa      xmm7, XMMWORD [wk(0)]   ; xmm7=tmp0L
    268    movdqa      xmm6, XMMWORD [wk(1)]   ; xmm6=tmp0H
    269 
    270    movdqa      xmm2, xmm4
    271    movdqa      xmm3, xmm0
    272    paddd       xmm4, xmm7              ; xmm4=data1L
    273    paddd       xmm0, xmm6              ; xmm0=data1H
    274    psubd       xmm2, xmm7              ; xmm2=data2L
    275    psubd       xmm3, xmm6              ; xmm3=data2H
    276 
    277    movdqa      xmm7, [GOTOFF(ebx,PD_DESCALE_P1_4)]  ; xmm7=[PD_DESCALE_P1_4]
    278 
    279    paddd       xmm4, xmm7
    280    paddd       xmm0, xmm7
    281    psrad       xmm4, DESCALE_P1_4
    282    psrad       xmm0, DESCALE_P1_4
    283    paddd       xmm2, xmm7
    284    paddd       xmm3, xmm7
    285    psrad       xmm2, DESCALE_P1_4
    286    psrad       xmm3, DESCALE_P1_4
    287 
    288    packssdw    xmm4, xmm0        ; xmm4=data1=(10 11 12 13 14 15 16 17)
    289    packssdw    xmm2, xmm3        ; xmm2=data2=(20 21 22 23 24 25 26 27)
    290 
    291    movdqa      xmm6, xmm1        ; transpose coefficients(phase 1)
    292    punpcklwd   xmm1, xmm4        ; xmm1=(00 10 01 11 02 12 03 13)
    293    punpckhwd   xmm6, xmm4        ; xmm6=(04 14 05 15 06 16 07 17)
    294    movdqa      xmm7, xmm2        ; transpose coefficients(phase 1)
    295    punpcklwd   xmm2, xmm5        ; xmm2=(20 30 21 31 22 32 23 33)
    296    punpckhwd   xmm7, xmm5        ; xmm7=(24 34 25 35 26 36 27 37)
    297 
    298    movdqa      xmm0, xmm1        ; transpose coefficients(phase 2)
    299    punpckldq   xmm1, xmm2        ; xmm1=[col0 col1]=(00 10 20 30 01 11 21 31)
    300    punpckhdq   xmm0, xmm2        ; xmm0=[col2 col3]=(02 12 22 32 03 13 23 33)
    301    movdqa      xmm3, xmm6        ; transpose coefficients(phase 2)
    302    punpckldq   xmm6, xmm7        ; xmm6=[col4 col5]=(04 14 24 34 05 15 25 35)
    303    punpckhdq   xmm3, xmm7        ; xmm3=[col6 col7]=(06 16 26 36 07 17 27 37)
    304 .column_end:
    305 
    306    ; -- Prefetch the next coefficient block
    307 
    308    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 0*32]
    309    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 1*32]
    310    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 2*32]
    311    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 3*32]
    312 
    313    ; ---- Pass 2: process rows, store into output array.
    314 
    315    mov         eax, [original_ebp]
    316    mov         edi, JSAMPARRAY [output_buf(eax)]  ; (JSAMPROW *)
    317    mov         eax, JDIMENSION [output_col(eax)]
    318 
    319    ; -- Even part
    320 
    321    pxor        xmm4, xmm4
    322    punpcklwd   xmm4, xmm1               ; xmm4=tmp0
    323    psrad       xmm4, (16-CONST_BITS-1)  ; psrad xmm4,16 & pslld xmm4,CONST_BITS+1
    324 
    325    ; -- Odd part
    326 
    327    punpckhwd   xmm1, xmm0
    328    punpckhwd   xmm6, xmm3
    329    movdqa      xmm5, xmm1
    330    movdqa      xmm2, xmm6
    331    pmaddwd     xmm1, [GOTOFF(ebx,PW_F256_F089)]    ; xmm1=(tmp2)
    332    pmaddwd     xmm6, [GOTOFF(ebx,PW_MF060_MF050)]  ; xmm6=(tmp2)
    333    pmaddwd     xmm5, [GOTOFF(ebx,PW_F106_MF217)]   ; xmm5=(tmp0)
    334    pmaddwd     xmm2, [GOTOFF(ebx,PW_F145_MF021)]   ; xmm2=(tmp0)
    335 
    336    paddd       xmm6, xmm1              ; xmm6=tmp2
    337    paddd       xmm2, xmm5              ; xmm2=tmp0
    338 
    339    ; -- Even part
    340 
    341    punpcklwd   xmm0, xmm3
    342    pmaddwd     xmm0, [GOTOFF(ebx,PW_F184_MF076)]  ; xmm0=tmp2
    343 
    344    movdqa      xmm7, xmm4
    345    paddd       xmm4, xmm0              ; xmm4=tmp10
    346    psubd       xmm7, xmm0              ; xmm7=tmp12
    347 
    348    ; -- Final output stage
    349 
    350    movdqa      xmm1, [GOTOFF(ebx,PD_DESCALE_P2_4)]  ; xmm1=[PD_DESCALE_P2_4]
    351 
    352    movdqa      xmm5, xmm4
    353    movdqa      xmm3, xmm7
    354    paddd       xmm4, xmm6              ; xmm4=data0=(00 10 20 30)
    355    paddd       xmm7, xmm2              ; xmm7=data1=(01 11 21 31)
    356    psubd       xmm5, xmm6              ; xmm5=data3=(03 13 23 33)
    357    psubd       xmm3, xmm2              ; xmm3=data2=(02 12 22 32)
    358 
    359    paddd       xmm4, xmm1
    360    paddd       xmm7, xmm1
    361    psrad       xmm4, DESCALE_P2_4
    362    psrad       xmm7, DESCALE_P2_4
    363    paddd       xmm5, xmm1
    364    paddd       xmm3, xmm1
    365    psrad       xmm5, DESCALE_P2_4
    366    psrad       xmm3, DESCALE_P2_4
    367 
    368    packssdw    xmm4, xmm3              ; xmm4=(00 10 20 30 02 12 22 32)
    369    packssdw    xmm7, xmm5              ; xmm7=(01 11 21 31 03 13 23 33)
    370 
    371    movdqa      xmm0, xmm4              ; transpose coefficients(phase 1)
    372    punpcklwd   xmm4, xmm7              ; xmm4=(00 01 10 11 20 21 30 31)
    373    punpckhwd   xmm0, xmm7              ; xmm0=(02 03 12 13 22 23 32 33)
    374 
    375    movdqa      xmm6, xmm4              ; transpose coefficients(phase 2)
    376    punpckldq   xmm4, xmm0              ; xmm4=(00 01 02 03 10 11 12 13)
    377    punpckhdq   xmm6, xmm0              ; xmm6=(20 21 22 23 30 31 32 33)
    378 
    379    packsswb    xmm4, xmm6              ; xmm4=(00 01 02 03 10 11 12 13 20 ..)
    380    paddb       xmm4, [GOTOFF(ebx,PB_CENTERJSAMP)]
    381 
    382    pshufd      xmm2, xmm4, 0x39        ; xmm2=(10 11 12 13 20 21 22 23 30 ..)
    383    pshufd      xmm1, xmm4, 0x4E        ; xmm1=(20 21 22 23 30 31 32 33 00 ..)
    384    pshufd      xmm3, xmm4, 0x93        ; xmm3=(30 31 32 33 00 01 02 03 10 ..)
    385 
    386    mov         edx, JSAMPROW [edi+0*SIZEOF_JSAMPROW]
    387    mov         esi, JSAMPROW [edi+1*SIZEOF_JSAMPROW]
    388    movd        XMM_DWORD [edx+eax*SIZEOF_JSAMPLE], xmm4
    389    movd        XMM_DWORD [esi+eax*SIZEOF_JSAMPLE], xmm2
    390    mov         edx, JSAMPROW [edi+2*SIZEOF_JSAMPROW]
    391    mov         esi, JSAMPROW [edi+3*SIZEOF_JSAMPROW]
    392    movd        XMM_DWORD [edx+eax*SIZEOF_JSAMPLE], xmm1
    393    movd        XMM_DWORD [esi+eax*SIZEOF_JSAMPLE], xmm3
    394 
    395    pop         edi
    396    pop         esi
    397 ;   pop         edx                     ; need not be preserved
    398 ;   pop         ecx                     ; unused
    399    POPPIC      ebx
    400    mov         esp, ebp                ; esp <- aligned ebp
    401    pop         esp                     ; esp <- original ebp
    402    pop         ebp
    403    ret
    404 
    405 ; --------------------------------------------------------------------------
    406 ;
    407 ; Perform dequantization and inverse DCT on one block of coefficients,
    408 ; producing a reduced-size 2x2 output block.
    409 ;
    410 ; GLOBAL(void)
    411 ; jsimd_idct_2x2_sse2(void *dct_table, JCOEFPTR coef_block,
    412 ;                     JSAMPARRAY output_buf, JDIMENSION output_col)
    413 ;
    414 
    415 %define dct_table(b)   (b) + 8          ; void *dct_table
    416 %define coef_block(b)  (b) + 12         ; JCOEFPTR coef_block
    417 %define output_buf(b)  (b) + 16         ; JSAMPARRAY output_buf
    418 %define output_col(b)  (b) + 20         ; JDIMENSION output_col
    419 
    420    align       32
    421    GLOBAL_FUNCTION(jsimd_idct_2x2_sse2)
    422 
    423 EXTN(jsimd_idct_2x2_sse2):
    424    push        ebp
    425    mov         ebp, esp
    426    push        ebx
    427 ;   push        ecx                     ; need not be preserved
    428 ;   push        edx                     ; need not be preserved
    429    push        esi
    430    push        edi
    431 
    432    GET_GOT     ebx                     ; get GOT address
    433 
    434    ; ---- Pass 1: process columns from input.
    435 
    436    mov         edx, POINTER [dct_table(ebp)]    ; quantptr
    437    mov         esi, JCOEFPTR [coef_block(ebp)]  ; inptr
    438 
    439    ; | input:                  | result:        |
    440    ; | 00 01 ** 03 ** 05 ** 07 |                |
    441    ; | 10 11 ** 13 ** 15 ** 17 |                |
    442    ; | ** ** ** ** ** ** ** ** |                |
    443    ; | 30 31 ** 33 ** 35 ** 37 | A0 A1 A3 A5 A7 |
    444    ; | ** ** ** ** ** ** ** ** | B0 B1 B3 B5 B7 |
    445    ; | 50 51 ** 53 ** 55 ** 57 |                |
    446    ; | ** ** ** ** ** ** ** ** |                |
    447    ; | 70 71 ** 73 ** 75 ** 77 |                |
    448 
    449    ; -- Odd part
    450 
    451    movdqa      xmm0, XMMWORD [XMMBLOCK(1,0,esi,SIZEOF_JCOEF)]
    452    movdqa      xmm1, XMMWORD [XMMBLOCK(3,0,esi,SIZEOF_JCOEF)]
    453    pmullw      xmm0, XMMWORD [XMMBLOCK(1,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    454    pmullw      xmm1, XMMWORD [XMMBLOCK(3,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    455    movdqa      xmm2, XMMWORD [XMMBLOCK(5,0,esi,SIZEOF_JCOEF)]
    456    movdqa      xmm3, XMMWORD [XMMBLOCK(7,0,esi,SIZEOF_JCOEF)]
    457    pmullw      xmm2, XMMWORD [XMMBLOCK(5,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    458    pmullw      xmm3, XMMWORD [XMMBLOCK(7,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    459 
    460    ; xmm0=(10 11 ** 13 ** 15 ** 17), xmm1=(30 31 ** 33 ** 35 ** 37)
    461    ; xmm2=(50 51 ** 53 ** 55 ** 57), xmm3=(70 71 ** 73 ** 75 ** 77)
    462 
    463    pcmpeqd     xmm7, xmm7
    464    pslld       xmm7, WORD_BIT          ; xmm7={0x0000 0xFFFF 0x0000 0xFFFF ..}
    465 
    466    movdqa      xmm4, xmm0              ; xmm4=(10 11 ** 13 ** 15 ** 17)
    467    movdqa      xmm5, xmm2              ; xmm5=(50 51 ** 53 ** 55 ** 57)
    468    punpcklwd   xmm4, xmm1              ; xmm4=(10 30 11 31 ** ** 13 33)
    469    punpcklwd   xmm5, xmm3              ; xmm5=(50 70 51 71 ** ** 53 73)
    470    pmaddwd     xmm4, [GOTOFF(ebx,PW_F362_MF127)]
    471    pmaddwd     xmm5, [GOTOFF(ebx,PW_F085_MF072)]
    472 
    473    psrld       xmm0, WORD_BIT          ; xmm0=(11 -- 13 -- 15 -- 17 --)
    474    pand        xmm1, xmm7              ; xmm1=(-- 31 -- 33 -- 35 -- 37)
    475    psrld       xmm2, WORD_BIT          ; xmm2=(51 -- 53 -- 55 -- 57 --)
    476    pand        xmm3, xmm7              ; xmm3=(-- 71 -- 73 -- 75 -- 77)
    477    por         xmm0, xmm1              ; xmm0=(11 31 13 33 15 35 17 37)
    478    por         xmm2, xmm3              ; xmm2=(51 71 53 73 55 75 57 77)
    479    pmaddwd     xmm0, [GOTOFF(ebx,PW_F362_MF127)]
    480    pmaddwd     xmm2, [GOTOFF(ebx,PW_F085_MF072)]
    481 
    482    paddd       xmm4, xmm5              ; xmm4=tmp0[col0 col1 **** col3]
    483    paddd       xmm0, xmm2              ; xmm0=tmp0[col1 col3 col5 col7]
    484 
    485    ; -- Even part
    486 
    487    movdqa      xmm6, XMMWORD [XMMBLOCK(0,0,esi,SIZEOF_JCOEF)]
    488    pmullw      xmm6, XMMWORD [XMMBLOCK(0,0,edx,SIZEOF_ISLOW_MULT_TYPE)]
    489 
    490    ; xmm6=(00 01 ** 03 ** 05 ** 07)
    491 
    492    movdqa      xmm1, xmm6              ; xmm1=(00 01 ** 03 ** 05 ** 07)
    493    pslld       xmm6, WORD_BIT          ; xmm6=(-- 00 -- ** -- ** -- **)
    494    pand        xmm1, xmm7              ; xmm1=(-- 01 -- 03 -- 05 -- 07)
    495    psrad       xmm6, (WORD_BIT-CONST_BITS-2)  ; xmm6=tmp10[col0 **** **** ****]
    496    psrad       xmm1, (WORD_BIT-CONST_BITS-2)  ; xmm1=tmp10[col1 col3 col5 col7]
    497 
    498    ; -- Final output stage
    499 
    500    movdqa      xmm3, xmm6
    501    movdqa      xmm5, xmm1
    502    paddd       xmm6, xmm4      ; xmm6=data0[col0 **** **** ****]=(A0 ** ** **)
    503    paddd       xmm1, xmm0      ; xmm1=data0[col1 col3 col5 col7]=(A1 A3 A5 A7)
    504    psubd       xmm3, xmm4      ; xmm3=data1[col0 **** **** ****]=(B0 ** ** **)
    505    psubd       xmm5, xmm0      ; xmm5=data1[col1 col3 col5 col7]=(B1 B3 B5 B7)
    506 
    507    movdqa      xmm2, [GOTOFF(ebx,PD_DESCALE_P1_2)]  ; xmm2=[PD_DESCALE_P1_2]
    508 
    509    punpckldq   xmm6, xmm3              ; xmm6=(A0 B0 ** **)
    510 
    511    movdqa      xmm7, xmm1
    512    punpcklqdq  xmm1, xmm5              ; xmm1=(A1 A3 B1 B3)
    513    punpckhqdq  xmm7, xmm5              ; xmm7=(A5 A7 B5 B7)
    514 
    515    paddd       xmm6, xmm2
    516    psrad       xmm6, DESCALE_P1_2
    517 
    518    paddd       xmm1, xmm2
    519    paddd       xmm7, xmm2
    520    psrad       xmm1, DESCALE_P1_2
    521    psrad       xmm7, DESCALE_P1_2
    522 
    523    ; -- Prefetch the next coefficient block
    524 
    525    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 0*32]
    526    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 1*32]
    527    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 2*32]
    528    prefetchnta [esi + DCTSIZE2*SIZEOF_JCOEF + 3*32]
    529 
    530    ; ---- Pass 2: process rows, store into output array.
    531 
    532    mov         edi, JSAMPARRAY [output_buf(ebp)]  ; (JSAMPROW *)
    533    mov         eax, JDIMENSION [output_col(ebp)]
    534 
    535    ; | input:| result:|
    536    ; | A0 B0 |        |
    537    ; | A1 B1 | C0 C1  |
    538    ; | A3 B3 | D0 D1  |
    539    ; | A5 B5 |        |
    540    ; | A7 B7 |        |
    541 
    542    ; -- Odd part
    543 
    544    packssdw    xmm1, xmm1              ; xmm1=(A1 A3 B1 B3 A1 A3 B1 B3)
    545    packssdw    xmm7, xmm7              ; xmm7=(A5 A7 B5 B7 A5 A7 B5 B7)
    546    pmaddwd     xmm1, [GOTOFF(ebx,PW_F362_MF127)]
    547    pmaddwd     xmm7, [GOTOFF(ebx,PW_F085_MF072)]
    548 
    549    paddd       xmm1, xmm7              ; xmm1=tmp0[row0 row1 row0 row1]
    550 
    551    ; -- Even part
    552 
    553    pslld       xmm6, (CONST_BITS+2)    ; xmm6=tmp10[row0 row1 **** ****]
    554 
    555    ; -- Final output stage
    556 
    557    movdqa      xmm4, xmm6
    558    paddd       xmm6, xmm1     ; xmm6=data0[row0 row1 **** ****]=(C0 C1 ** **)
    559    psubd       xmm4, xmm1     ; xmm4=data1[row0 row1 **** ****]=(D0 D1 ** **)
    560 
    561    punpckldq   xmm6, xmm4     ; xmm6=(C0 D0 C1 D1)
    562 
    563    paddd       xmm6, [GOTOFF(ebx,PD_DESCALE_P2_2)]
    564    psrad       xmm6, DESCALE_P2_2
    565 
    566    packssdw    xmm6, xmm6              ; xmm6=(C0 D0 C1 D1 C0 D0 C1 D1)
    567    packsswb    xmm6, xmm6              ; xmm6=(C0 D0 C1 D1 C0 D0 C1 D1 ..)
    568    paddb       xmm6, [GOTOFF(ebx,PB_CENTERJSAMP)]
    569 
    570    pextrw      ebx, xmm6, 0x00         ; ebx=(C0 D0 -- --)
    571    pextrw      ecx, xmm6, 0x01         ; ecx=(C1 D1 -- --)
    572 
    573    mov         edx, JSAMPROW [edi+0*SIZEOF_JSAMPROW]
    574    mov         esi, JSAMPROW [edi+1*SIZEOF_JSAMPROW]
    575    mov         word [edx+eax*SIZEOF_JSAMPLE], bx
    576    mov         word [esi+eax*SIZEOF_JSAMPLE], cx
    577 
    578    pop         edi
    579    pop         esi
    580 ;   pop         edx                     ; need not be preserved
    581 ;   pop         ecx                     ; need not be preserved
    582    pop         ebx
    583    pop         ebp
    584    ret
    585 
    586 ; For some reason, the OS X linker does not honor the request to align the
    587 ; segment unless we do this.
    588    align       32